]]>As both recreational and medical cannabis legalization continues to progress across the country, each state is tasked with developing regulatory requirements to ensure that customers and patients receive clean cannabis for consumption. This requires cannabis to undergo laboratory testing that analyzes the presence of microbial impurities including yeast and mold.

Some states, such as Colorado, Nevada, Maine, Illinois and Massachusetts use total yeast and mold count testing (TYMC) and set a maximum yeast and mold count threshold that cultivators must fall below. Other states, such as California, require the detection of species-specific strains of Aspergillus mold (A. fumigatus, A. flavus, A. niger and A. terreus), which requires analyzing the DNA of a cannabis sample through polymerase chain reaction testing, also known as PCR.

Differences in state regulations can lead to different microbiological techniques implemented for testing.Before diving in further, it is important to understand the scientific approach. Laboratory testing requirements for cannabis can be separated into two categories: analytical chemistry methods and microbiological methods.

Analytical chemistry is the science of qualitatively and quantitatively determining the chemical components of a substance, and usually consists of some kind of separation followed by detection. Analytical methods are used to uncover the potency of cannabis, analyze the terpene profile and to detect the presence of pesticides, chemical residues, residuals solvents, heavy metals and mycotoxins. Analytical testing methods are performed first before proceeding to microbiological methods.

Microbiological methods dive deeper into cannabis at a cellular level to uncover microbial impurities such as yeast, mold and bacteria. The techniques utilized in microbiological methods are very different from traditional analytical chemistry methods in both the way they are performed and target of the analysis. Differences in state regulations can lead to different microbiological techniques implemented for testing. There are a variety of cell and molecular biology techniques that can be used for detecting microbial impurities, but most can be separated into two categories:

Methods to determine total microbial cell numbers, which typically utilizes cell culture, which involves growing cells in favorable conditions and plating, spreading the sample evenly in a container like a petri dish. The total yeast and mold count (TYMC) test follows this method.

Molecular methods intended to detect specific species of mold, such as harmful aspergillus mold strains, which typically involves testing for the presence of unique DNA sequences such as Polymerase Chain Reaction (PCR).

Among states that have legalized some form of cannabis use and put forth regulations, there appears to be a broad consensus that the laboratories should test for potency (cannabinoids concentration), pesticides (or chemical residues) and residual solvents at a minimum. On the other hand, microbial testing requirements, particularly for mold, appear to vary greatly from state to state. Oregon requires random testing for mold and mildew without any details on test type. In Colorado, Nevada, Maine, Illinois and Massachusetts, regulations explicitly state the use of TYMC for the detection of mold. In California, the recently released emergency regulations require testing for specific species of Aspergillus mold (A. fumigatus, A. flavus, A. niger and A. terreus), which are difficult to differentiate on a plate and would require a DNA-based approach. Since there are differences in costs associated and data produced by these methods, this issue will impact product costs for cultivators, which will affect cannabis prices for consumers.

]]>https://www.cannabisindustryjournal.com/feature_article/an-insiders-view-how-labs-conduct-cannabis-mold-testing/feed/0NCIA’s Cannabis Business Summithttps://www.cannabisindustryjournal.com/event/ncias-cannabis-business-summit/
Mon, 19 Feb 2018 22:35:42 +0000https://www.cannabisindustryjournal.com/?post_type=event&p=9171Cannabis Business Summit & Expo was the winner of Trade Show Executive’s Fastest 50 Award in 2016, honoring the fastest-growing trade shows held in the U.S., and the winner of The Denver Post’s The Cannabist Golden Pineapple Award in 2016 for Best Business Event.

The annual summit, hosted by the cannabis industry’s only national trade association, returns to the Bay Area, the epicenter of the cannabis movement, to bring together more than 6,000 of the industry’s best and brightest minds.

Serious, like-minded entrepreneurs will convene for three days to learn how to grow their businesses and to achieve new levels of success in five all-encompassing educational tracks.

Cannabis-testing laboratories have the challenge of removing a variety of unwanted matrix components from plant material prior to running extracts on their LC-MS/MS or GC-MS. The complexity of the cannabis plant presents additional analytical challenges that do not need to be accounted for in other agricultural products. Up to a third of the overall mass of cannabis seed, half of usable flower and nearly all extracts can be contributed to essential oils such as terpenes, flavonoids and actual cannabinoid content1. The biodiversity of this plant is exhibited in the over 2,000 unique strains that have been identified, each with their own pigmentation, cannabinoid profile and overall suggested medicinal use2. While novel methods have been developed for the removal of chlorophyll, few, if any, sample preparation methods have been devoted to removal of other colored pigments from cannabis.

Cannabis samples following QuEChERS extraction

Sample Preparation

Cannabis samples from four strains of plant (Purple Drink, Tahoe OG, Grand Daddy and Agent Orange) were hydrated using deionized water. Following the addition of 10 mL acetonitrile, samples were homogenized using a SPEX Geno/Grinder and stainless steel grinding balls. QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) non-buffered extraction salts were then added and samples were shaken. Following centrifugation, an aliquot of the supernatant was transferred to various blends of dispersive SPE (dSPE) salts packed into centrifugation tubes. All dSPE tubes were vortexed prior to being centrifuged. Resulting supernatant was transferred to clear auto sampler vials for visual analysis. Recoveries of 48 pesticides and four mycotoxins were determined for the two dSPE blends that provided the most pigmentation removal.

Seven dSPE blends were evaluated for their ability to remove both chlorophyll and purple pigmentation from cannabis plant material:

150 mg MgSO4, 50 mg PSA, 50 mg C18, 50 mg Chlorofiltr®

150 mg MgSO4, 50 mg C18, 50 mg Chlorofiltr®

150 mg MgSO4, 50 mg PSA

150 mg MgSO4, 25 mg C18

150 mg MgSO4, 50 mg PSA, 50 mg C18

150 mg MgSO4, 25 mg PSA, 7.5 mg GCB

150 mg MgSO4, 50 mg PSA, 50 mg C18, 50 mg GCB

Based on the coloration of the resulting extracts, blends A, F and G were determined to be the most effective in removing both chlorophyll (all cannabis strains) and purple pigments (Purple Drink and Grand Daddy). Previous research regarding the ability of large quantities of GCB to retain planar pesticides allowed for the exclusion of blend G from further analyte quantitation3. The recoveries of the 48 selected pesticides and four mycotoxins for blends A and F were determined.

Grand Daddy following various dSPE cleanups

Summary

A blend of MgSO4, C18, PSA and Chlorofiltr® allowed for the most sample clean up, without loss of pesticides and mycotoxins, for all cannabis samples tested. Average recovery of the 47 pesticides and five mycotoxins using the selected dSPE blend was 75.6% were as the average recovery when including GCB instead of Chlorofiltr® was 67.6%. Regardless of the sample’s original pigmentation, this blend successfully removed both chlorophyll and purple hues from all strains tested. The other six dSPE blends evaluated were unable to provide the sample clean up needed or had previously demonstrated to be detrimental to the recovery of pesticides routinely analyzed in cannabis.

References

(1) Recommended methods for the identification and analysis of cannabis and cannabis products, United Nations Office of Drugs and Crime (2009)

]]>With the state led legalization of both adult recreational and medical cannabis, there is a need for comprehensive and reliable analytical testing to ensure consumer safety and drug potency. Cannabis-testing laboratories receive high volumes of test requests from cannabis cultivators for testing quantitative and qualitative aspects of the plant. The testing market is growing as more states bring in stricter enforcement policies on testing. As the number of testing labs grow, it is anticipated that the laboratories that are now servicing other markets, including high throughput contract labs, will cross into cannabis testing as regulations free up. As the volume of tests each lab performs increases, the need for laboratories to make effective use of time and resource management, such as ensuring accurate and quick results, reports, regulatory compliance, quality assurance and many other aspects of data management becomes vital in staying competitive.

Cannabis Testing Workflows

To be commercially competitive, testing labs offer a comprehensive range of testing services. These services are available for both the medical and recreational cannabis markets, including:

Detection and quantification of both acid and neutral forms of cannabinoids

Screening for pesticide levels

Monitoring water activity to indicate the possibility of microbiological contamination

Moisture content measurements

Terpene profiling

Residual solvents and heavy metal testing

Fungi, molds, mycotoxin testing and many more

Although the testing workflows differ for each test, here is a basic overview of the operations carried out in a cannabis-testing lab:

Cannabis samples are received.

The samples are processed using techniques such as grinding and homogenization. This may be followed by extraction, filtration and evaporation.

A few samples will be isolated and concentrated by dissolving in solvents, while others may be derivatized using HPLC or GC reagents

The processed samples are then subjected to chromatographic separation using techniques such as HPLC, UHPLC, GC and GC-MS.

The separated components are then analyzed and identified for qualitative and quantitative analysis based on specialized standards and certified reference materials.

The quantified analytical data will be exported from the instruments and compiled with the corresponding sample data.

The test results are organized and reviewed by the lab personnel.

The finalized test results are reported in a compliant format and released to the client.

In order to ensure that cannabis testing laboratories function reliably, they are obliged to follow and execute certain organizational and regulatory protocols throughout the testing process. These involve critical factors that determine the accuracy of testing services of a laboratory.

Factors Critical to a Cannabis Testing Laboratory

Accreditations & Regulatory Compliance: Cannabis testing laboratories are subject to regulatory compliance requirements, accreditation standards, laboratory practices and policies at the state level. A standard that most cannabis testing labs comply to is ISO 17025, which sets the requirements of quality standards in testing laboratories. Accreditation to this standard represents the determination of competence by an independent third party referred to as the “Accreditation Body”. Accreditation ensures that laboratories are adhering to their methods. These testing facilities have mandatory participation in proficiency tests regularly in order to maintain accreditation.

Quality Assurance, Standards & Proficiency Testing: Quality assurance is in part achieved by implementing standard test methods that have been thoroughly validated. When standard methods are not available, the laboratory must validate their own methods. In addition to using valid and appropriate methods, accredited laboratories are also required to participate in appropriate and commercially available Proficiency Test Program or Inter-Laboratory Comparison Study. Both PT and ILC Programs provide laboratories with some measure of their analytic performance and compare that performance with other participating laboratories.

Real-time Collaboration: Testing facilities generate metadata such as data derived from cannabis samples and infused products. The testing status and test results are best served for compliance and accessibility when integrated and stored on a centralized platform. This helps in timely data sharing and facilitates informed decision making, effective cooperation and relationships between cannabis testing facilities and growers. This platform is imperative for laboratories that have grown to high volume throughput where opportunities for errors exist. By matching test results to samples, this platform ensures consistent sample tracking and traceability. Finally, the platform is designed to provide immediate, real-time reporting to individual state or other regulatory bodies.

Personnel Management: Skilled scientific staff in cannabis-testing laboratories are required to oversee testing activities. Staff should have experience in analytical chromatography instruments such as HPLC and GC-MS. Since samples are often used for multi-analytes such as terpenes, cannabinoids, pesticides etc., the process often involves transferring samples and tests from one person to another within the testing facility. A chain of custody (CoC) is required to ensure traceability and ‘ownership’ for each person involved in the workflow.

LIMS for Laboratory Automation

Gathering, organizing and controlling laboratory-testing data can be time-consuming, labor-intensive and challenging for cannabis testing laboratories. Using spreadsheets and paper methods for this purpose is error-prone, makes data retrieval difficult and does not allow laboratories to easily adhere to regulatory guidelines. Manual systems are cumbersome, costly and lack efficiency. One way to meet this challenge is to switch to automated solutions that eliminate many of the mundane tasks that utilize valuable human resources.. Laboratory automation transforms the data management processes and as a result, improves the quality of services and provides faster turnaround time with significant cost savings. Automating the data management protocol will improve the quality of accountability, improve technical efficiency, and improve fiscal resources.

Real Time Test Status in CloudLIMS

A Laboratory Information Management System (LIMS) is a software tool for testing labs that aids efficient data management. A LIMS organizes, manages and communicates all laboratory test data and related information, such as sample and associated metadata, tests, Standard Operating Procedures (SOPs), test reports, and invoices. It also enables fully automated data exchange between instruments such as HPLCs, GC-FIDs, etc. to one consolidated location, thereby reducing transcription errors.

How LIMS Helps Cannabis Testing Labs

LIMS are much more capable than spreadsheets and paper-based tools for streamlining the analytical and operational lab activities and enhances the productivity and quality by eliminating manual data entry. Cloud-enabled LIMS systems such as CloudLIMS are often low in the total cost of acquisition, do not require IT staff and are scalable to help meet the ever changing business and regulatory compliance needs. Some of the key benefits of LIMS for automating a cannabis-testing laboratory are illustrated below [Table 1]:

]]>EVIO Labs recently became the first cannabis laboratory in Florida to obtain ISO 17025 accreditation. Perry Johnson Laboratory Accreditation, Inc. (PJLA), an organization that provides third-party assessments to ISO/IEC 17025, accredited EVIO Labs. The assessment process that lead to ISO 17025 accreditation for EVIO Labs included a thorough review of their quality management system, their capability to perform potency and contaminant testing for cannabis products.

Tracy Szerszen, president and operations manager at PJLA, encourages this international standard for laboratories to provide confidence to end-users that the test results they receive are reliable. She says laboratories that achieve this accreditation are showing they have the proper tools, equipment and staff to provide accurate testing. “It is a very critical component of the industry, and becoming accredited provides the assurance that laboratories are performing to the highest standard,” says Szerszen. “EVIO Labs has taken the right step in their commitment towards meeting this standard and providing clean and safe cannabis for the patients of Florida.”

EVIO Labs provides cannabis testing for cannabinoid and terpene profiles, microbiological and pesticides contamination, residual solvent, heavy metals, mycotoxins, water activity and moisture content. Chris Martinez, co-founder and president of EVIO Labs Florida explains that the Florida Department of Health mandates that an independent third-party laboratory tests medical cannabis to ensure that these products are safe for human consumption. Martinez says their first priority is the safety of their patients, and ensuring that EVIO Labs provides clean and safe cannabis for Florida.

Chris Martinez, co-founder and president of EVIO Labs Florida

Martinez launched their laboratory with some help from Shimadzu last year. “Our Broward lab is powered by Shimadzu with over $1.2M in the latest testing equipment utilizing LCMS technology with the world’s fastest polarity switching time of 5 m/sec and scan speeds of 30,000 u/sec with UF Qarray sensitivity 90 times that of previously available technologies,” says Martinez. According to Martinez, their licensing agreement with EVIO Labs (OTC:SGBYD) marked a first for the publicly traded company with exclusivity in the Florida market. The agreement includes proprietary testing methodologies, operating procedures, training and support.

Every certificate of analysis is reviewed by a lab director with over 20 years of experience operating in FDA regulated labs. Martinez says that EVIO has some of the most advanced technology in the industry, which provides them the opportunity to quickly provide results, frequently as fast as a 24-hour period. Martinez and his team are currently building a 3,300 square-foot laboratory in Gainesville, which is expected to be running by March of this year.

]]>https://www.cannabisindustryjournal.com/news_article/evio-labs-the-first-accredited-cannabis-lab-in-florida/feed/0Growing Pains a Month Into California’s Market Launchhttps://www.cannabisindustryjournal.com/news_article/growing-pains-a-month-into-californias-market-launch/
https://www.cannabisindustryjournal.com/news_article/growing-pains-a-month-into-californias-market-launch/#respondWed, 31 Jan 2018 17:52:11 +0000https://www.cannabisindustryjournal.com/?post_type=news_article&p=9105California’s new market is adjusting well to the changes, but side effects of the regulations are beginning to show.

]]>For about a month now, California’s adult use market has been open for business and the market is booming. About thirty days into the world’s largest adult use market launch, we are beginning to see side effects of the growing pains that come with adjusting the massive industry.

Consumers are also feeling sticker shock as the new taxes add up to a 40% increase in price.While the regulatory and licensing roll out has been relatively smooth, some municipalities are slower than others in welcoming the adult use cannabis industry. It took Los Angeles weeks longer than other counties to begin licensing dispensaries. Meanwhile, retailers in San Diego say the first month brought a huge influx of customers, challenging their abilities to meet higher-than-expected demand.

Businesses are struggling to deal with large amounts of cash, but California State Treasurer John Chiang may have a solution in store. Yesterday, his department announced they are planning to create a taxpayer-backed bank for cannabis businesses.

In the regulatory realm, some are concerned that a loophole in the rules allows bigger cultivation operations to squeeze out the competition from smaller businesses. The California Growers Association filed a lawsuit against the California Department of Food and Agriculture to try and close this loophole, hoping to give smaller cultivators a leg up before bigger companies can dominate the market.

The Bureau of Cannabis Control (known as just “The Bureau”) began holding meetings and workshops to help cannabis businesses get acquainted with the new rules. Public licensing workshops in Irvine and San Diego held last week were designed to focus on information required for licensing and resources for planning. The Bureau also held their first cannabis advisory committee meeting, as well as announcing new subcommittees and an input survey to help the Bureau better meet business needs.

On the lab-testing front, the state has phased in cannabinoids, moisture content, residual solvent, pesticide, microbial impurities and homogeneity testing. On July 1, the state will phase in additional residual solvent and pesticide testing in addition to foreign material testing. At the end of 2018, they plan on requiring terpenoids, mycotoxins, heavy metals and water activity testing as well.

]]>When Nevada legalized adult use sales this past summer, the market exploded and undoubtedly flooded licensed testing labs with samples to get products on shelves. In August, roughly a month after the start of adult use sales, a Las Vegas cannabis-testing lab, G3 Labs, had their license suspended for an unknown compliance issue.

“We can’t disclose the details of the suspension, including anything about penalties,” said Klapstein. “Under NRS 360.255, the information is confidential.”Then in late December, the Nevada Department of Taxation, one of the bodies tasked with regulating the state’s industry, announced in an email they suspended two more cannabis testing lab licenses. Certified Ag Lab in Sparks, Nevada and Cannex Nevada, LLC, in Las Vegas (also known as RSR Analytical Laboratories) both had their licenses suspended on December 22 and December 26 respectively.

Stephanie Klapstein, spokeswoman for the Department of Taxation, told the Reno Gazette Journal that both of those labs were not following proper protocols. “During separate, routine inspections, Department inspectors discovered that these two labs were not following proper lab procedures and good laboratory practices,” says Klapstein. “Their licenses were suspended until those deficiencies were corrected.”

According to the Reno Gazette Journal, both of those labs had their licenses reinstated and have since resumed normal business. During their license suspension, the labs were not allowed to operate and the department directed licensed cannabis businesses to submit samples to other labs. The department also directed the suspended labs in the email to coordinate with their clients who had samples in for testing; to either have their samples transferred to a different lab or a new sample taken for another lab to test. They did note that no product recalls were deemed necessary because of the suspension.

In that same email, the department directed licensed cannabis businesses to state-licensed labs in good standing, including 374 Labs, ACE Analytical Laboratory, DB Labs, Digipath Labs, MM Lab and NV CANN Lab. But on the department’s website, it says there are 11 licensed testing labs.

Back in September when we reported on the first lab license suspension, Klapstein told CIJ that under state law they couldn’t discuss any reasons behind why they suspended licenses. “We can’t disclose the details of the suspension, including anything about penalties,” said Klapstein. “Under NRS 360.255, the information is confidential.”

Because of that confidentiality, there are a number of questions left unanswered: With three lab licenses suspended in the first six months of the Nevada’s adult use market being open, how are testing labs keeping up with the market’s pace? What did those suspended labs do wrong? Do the regulations adequately protect public health and safety?

]]>Sunrise Genetics, Inc., the parent company of Marigene and Hempgene, announced their partnership with New Brunswick Research & Productivity Council (RPC) this week, according to a press release. The company has been working in the United States for a few years now doing genomic sequencing and genetic research with headquarters based in Fort Collins, CO. This new partnership, compliant with Health Canada sample submission requirements, allows Canadian growers to submit plants for DNA extraction and genomic sequencing.

Sunrise Genetics researches different cannabis cultivars in the areas of target improvement of desired traits, accelerated breeding and expanding the knowledge base of cannabis genetics. One area they have been working on is genetic plant identification, which uses the plant’s DNA and modern genomics to create authentic, reproducible, commercial-ready strains.

Matt Gibbs, president of Sunrise Genetics, says he is very excited to get working on cannabis DNA testing in Canada. “RPC has a long track record of leadership in analytical services, especially as it relates to DNA and forensic work, giving Canadian growers their first real option to submit their plant samples for DNA extraction through proper legal channels,” says Gibbs. “The option to pursue genomic research on cannabis is now at Canadian cultivator’s fingertips.”

Canada’s massive new cannabis industry, which now has legal recreational and medical use, sales and cultivation, previously has not had many options for genetic testing. Using their genetic testing capabilities, they hope this partnership will better help Canadian cultivators easily apply genomic testing for improved plant development. “I’m looking forward to working with more Canadian cultivators and breeders; the opportunity to apply genomics to plant improvement is a win-win for customers seeking transparency about their Cannabis product and producers seeking customer retention through ‘best-in-class’ cannabis and protectable plant varieties,” says Gibbs. The partnership also ensures samples will follow the required submission process for analytical testing, but adding the service option of genetic testing so growers can find out more about their plants beyond the regular gamut of tests.

RPC is a New Brunswick provincial research organization (PRO), a research and technology organization (RTO) that offers R&D testing and technical services. With 130 scientists, engineers and technologists, RPC offers a wide variety of testing services, including air quality, analytical chemistry of cannabis, material testing and a large variety of pilot facilities for manufacturing research and development.

They have over 100 accreditations and certifications including an ISO 17025 scope from the Standards Council of Canada (SCC) and is ISO 9001:2008 certified. This genetic testing service for cannabis plants is the latest development in their repertoire of services. “This service builds on RPC’s established genetic strengths and complements the services we are currently offering the cannabis industry,” says Eric Cook, chief executive officer of RPC.

]]>https://www.cannabisindustryjournal.com/feature_article/sunrise-genetics-partners-with-rpc-begins-genetic-testing-in-canada/feed/0California Rolls Out Licensing For Cannabis Businesseshttps://www.cannabisindustryjournal.com/news_article/california-rolls-out-licensing-for-cannabis-businesses/
https://www.cannabisindustryjournal.com/news_article/california-rolls-out-licensing-for-cannabis-businesses/#respondTue, 19 Dec 2017 20:22:17 +0000https://www.cannabisindustryjournal.com/?post_type=news_article&p=8941The first temporary licenses under the new regulatory scheme were issued last week. So far, 43 licenses have been awarded.

]]>Last week, the Bureau of Cannabis Control issued the first licenses for California’s new market. The first license went to Moxie, a cannabis distribution company out of Lynwood.
The search feature for the list of licenses issued so far

As of the publication of this article, the Bureau, the state authority tasked with leading the regulation of the industry, has issued 43 temporary licenses. So far, four laboratories have received licenses, along with a number of retailers, distributors, microbusinesses in both medical and adult-use markets.

The labs to receive their temporary licenses so far are pH Solutions, Steep Hill Labs, Pure Analytics and ORCA Cannalytics. Judging by the number of temporary medical and adult-use licenses awarded so far, it appears the Bureau is trying to issue a similar amount for each sector, distributing the number of licenses between the two equitably.

You can find the list of licensees here, and search between the dates of 12/15/17 to 1/2/18 to get the most up-to-date list of licenses awarded. “Last week, we officially launched our online licensing system, and today we’re pleased to issue the first group of temporary licenses to cannabis businesses that fall under the Bureau’s jurisdiction,” says Lori Ajax, Bureau of Cannabis Control Chief. “We plan to issue many more before January 1.”

According to the press release, temporary licenses are only issued to applicants with prior local authorization in the form of a license or permit from the jurisdiction where the business is. Those licenses will become effective on January 1, 2018. The temporary licenses will work for 120 days, or May 1, 2018, after which businesses will need to have a permanent license to continue operating.

More than 1,900 users have registered with the Bureau’s online system, and more than 200 applications have been submitted, according to the press release.

The various regulatory bodies in California have worked diligently for months now to roll out proposed emergency regulations, setting strict requirements for manufacturers, growers, retailers and testing labs. Manufacturing regulations, including specific labeling, packaging and processing requirements, give a good snapshot of how regulators plan to move forward. Testing requirements could also be significantly firmer, with rules for documentation, sample sizes, sampling procedures, storage and transportation.

Yet when the adult-use sales become fully legal on January 1, 2018, those regulations will not be fully implemented.

Donald Land, a UC Davis chemistry professor and chief scientific consultant at Steep Hill Labs Inc., told The Associated Press, “Buyer beware.” There will be a six-month range where existing inventory will be allowed on the shelves, products that might not meet the standards of the new rules. So dispensaries will get half a year of sales before all products have to meet the new, stricter testing requirements.

]]>Editor’s note: This article should serve as a foundation of knowledge for yeast and mold in cannabis. Beginning in January 2018, we will publish a series of articles focused entirely on yeast and mold, discussing topics such as TYMC testing, preventing yeast and mold in cultivation and treatment methods to reduce yeast and mold.

Cannabis stakeholders, including cultivators, extractors, brokers, distributors and consumers, have been active in the shadows for decades. With the legalization of recreational adult use in several states, and more on the way, safety of the distributed product is one of the main concerns for regulators and the public. Currently, Colorado1, Nevada and Canada2 require total yeast and mold count (TYMC) compliance testing to evaluate whether or not cannabis is safe for human consumption. As the cannabis industry matures, it is likely that TYMC or other stringent testing for yeast and mold will be adopted in the increasingly regulated medical and recreational markets.

The goal of this article is to provide general information on yeast and mold, and to explain why TYMC is an important indicator in determining cannabis safety.

Yeast & Mold

Yeast and mold are members of the fungi family. Fungus, widespread in nature, can be found in the air, water, soil, vegetation and in decaying matter. The types of fungus found in different geographic regions vary based upon humidity, soil and other environmental conditions. In general, fungi can grow in a wide range of pH environments and temperatures, and can survive in harsh conditions that bacteria cannot. They are not able to produce their own food like plants, and survive by breaking down material from their surroundings into nutrients. Mold cannot thrive in an environment with limited oxygen, while yeast is able to grow with or without oxygen. Most molds, if grown for a long enough period, can be detected visually, while yeast growth is usually detected by off-flavor and fermentation.

Due to their versatility, it is rare to find a place or surface that is naturally free of fungi or their spores. Damp conditions, poor air quality and darker areas are inviting environments for yeast and mold growth.

Cannabis plants are grown in both indoor and outdoor conditions. Plants grown outdoors are exposed to wider ranges and larger populations of fungal species compared to indoor plants. However, factors such as improper watering, the type of soil and fertilizer and poor air circulation can all increase the chance of mold growth in indoor environments. Moreover, secondary contamination is a prevalent risk from human handling during harvest and trimming for both indoor and outdoor-grown cannabis. If humidity and temperature levels of drying and curing rooms are not carefully controlled, the final product could also easily develop fungi or their growth by-product.

What is TYMC?

TYMC, or total yeast and mold count, is the number of colony forming units present per gram of product (CFU/g). A colony forming unit is the scientific means of counting and reporting the population of live bacteria or yeast and mold in a product. To determine the count, the cannabis sample is plated on a petri dish which is then incubated at a specific temperature for three to five days. During this time, the yeast and mold present will grow and reproduce. Each colony, which represents an individual or a group of yeast and mold, produces one spot on the petri dish. Each spot is considered one colony forming unit.

Why is TYMC Measured?

TYMC is an indicator of the overall cleanliness of the product’s life cycle: growing environment, processing conditions, material handling and storage facilities. Mold by itself is not considered “bad,” but having a high mold count, as measured by TYMC, is alarming and could be detrimental to both consumers and cultivators.

Aspergillus species nigerPhoto: Carlos de Paz, Flickr

The vast majority of mold and yeast present in the environment are indeed harmless, and even useful to humans. Some fungi are used commercially in production of fermented food, industrial alcohol, biodegradation of waste material and the production of antibiotics and enzymes, such as penicillin and proteases. However, certain fungi cause food spoilage and the production of mycotoxin, a fungal growth by-product that is toxic to humans and animals. Humans absorb mycotoxins through inhalation, skin contact and ingestion. Unfortunately, mycotoxins are very stable and withstand both freezing and cooking temperatures. One way to reduce mycotoxin levels in a product is to have a low TYMC.

Aspergillus flavus on culture.Photo: Iqbal Osman, Flickr

Yeast and mold have been found to be prevalent in cannabis in both current and previous case studies. In a 2017 UC Davis study, 20 marijuana samples obtained from Northern California dispensaries were found to contain several yeast and mold species, including Cryptococcus, Mucor, Aspergillus fumigatus, Aspergillus niger, and Aspergillus flavus.3 The same results were reported in 1983, when marijuana samples collected from 14 cannabis smokers were analyzed. All of the above mold species in the 2017 study were present in 13 out of 14 marijuana samples.4

Aspergillus species niger, flavus, and fumigatus are known for aflatoxin production, a type of dangerous mycotoxin that can be lethal.5 Once a patient smokes and/or ingests cannabis with mold, the toxins and/or spores can thrive inside the lungs and body.6, 7 There are documented fatalities and complications in immunocompromised patients smoking cannabis with mold, including patients with HIV and other autoimmune diseases, as well as the elderly.8, 9, 10, 11

For this reason, regulations exist to limit the allowable TYMC counts for purposes of protecting consumer safety. At the time of writing this article, the acceptable limit for TYMC in cannabis plant material in Colorado, Nevada and Canada is ≤10,000 CFU/g. Washington state requires a mycotoxin test.12 California is looking into testing for specific Aspergillus species as a part of their requirement. As the cannabis industry continues to grow and advance, it is likely that additional states will adopt some form of TYMC testing into their regulatory testing requirements.